Comment 6 for bug 1642386

Oh, you may also want to try moving lists/ out of the way and running apt update again.

And perhaps send me a tarball of /var/lib/apt and /etc/apt - then I might have luck reproducing it.

If you want to, you could try bisecting this in the apt git repo, starting with

git bisect start
git bisect good 1.2.12
git bisect bad 1.2.15
git bisect run sh ./script.sh

where script.sh is:

#!/bin/sh
make fast || exit 125
sudo LD_LIBRARY_PATH=$PWD/build/bin/ ./build/bin/apt-get update -o Dir::Bin::Methods="$PWD/build/bin/methods/" 2>&1 | tee update.log

if grep "was encountered" update.log; then
  exit 1
fi

exit 0